Antirattler spring and lever system for centrifugal clutches



April 26, 1949.

Filed Oct. 30, 1944 H. NUTT El AL ANTIRATTLER SPRING AND LEVER SYSTEM FOR GENTRIFUGAL CLUTCHES 5 Sheets-Sheet 1 firo and April 26, 1949. H. NUTT ETAL ANTIRATTLER SFRING AND LEVER SYSTEM FOR CENTRIFUGAL CLUTCHES 3 Sheets-Sheet 2 Filed Oct. 30, 1944 iyllllm I H. NUTT ET AL ANTIR T L SPRING AND LEVER SYSTEM N'IRIFUGAL GLUTCHES April 26, 1949.

3 Sheets-Sheet 3 Filed Oct. 50, 1944 fill/6711 0715 Haralci and Patented Apr. 26, 1949 ANTIRATTLER SPRING AND LEVER. SYSTEM FOR CENTRIFUGAL CLUTCHES Harold Nutt and Leo W. Cook, Chicago, IIL, as-

slgnors to Borg-Warner Corporation, Chicago, Ill., a corporation of Illinois Application October 30. 1944, Serial No. 561,009

9 Claims.

This invention relates to clutches such as used in motor driven vehicles, and more particularly to clutches of the friction type. Specifically. the present improvements are directed to the construction and arrangement of the control levers; the weights for centrifugally operating the clutch; and the reaction springs for the control levers.

It is one of the principal objects of this invention to simplify the construction of a clutch such as contemplated herein, and to improve the effiency and operation of such clutch.

Another principal object is to provide control lever arrangements wherein the lever has a plurality of fulcrums at least one of which includes an element that is adapted to bodily swing upon one edge during rocking of the lever.

A further principal object is to provide a plurality of iulcrums for a clutch control lever one of such fulcrums being located on the spring supporting member of the clutch. and the other fulcrums being on a support carried by the clutch cover.

Still another principal object hereof resides in the provision of a clutch control lever having a fulcrum comprised of a strut having a swinging teetering movement in an eye-bolt which supports and connects the spring supporting member of the clutch to the cover plate.

A still further object is to provide a spring 1 member for a clutch control lever to prevent rattle or backlash, such spring member at its radially outer end bearing against the clutch spring ring and at its inner end against the control lever with an intermediate portion contacting the clutch cover. In this spring arrangement the two outer points of contact of the backlash spring are substantially in line with two corresponding outer fulcrums of the lever. Thus, the tension of the spring will not vary appreciably in different positions of the lever and there is no possibility of fatigue of the spring because it is not compressed beyond its initial tension during operation of the clutch.

Additional objects, aims, and advantages of the invention contemplated herein will be apparent to persons skilled in the art after the construction and operation of the clutch control is understood from the within description.

It is preferred to accomplish the numerous objects of this invention and to practice the same in substantially the manner hereinafter described and as more particularly pointed out in the claims, reference being made to the accompanymg drawings that are a part of this specification, wherein:

Fig. 1 is a vertical axial sectional view of a centrifugal clutch showing an embodiment of the invention contemplated herein;

Fig. 2 is a fragmentary side elevation of a portion of the clutch shown in Fig. 1 with the cover plate omitted;

Fig. 3 is a sectional view along the plane of line 3-3 of Fig. 2;

Fig. 4 is a perspective view of the spring for the control lever;

Fig. 5 is a fragmentary view of modified arrangement of the control lever and spring; and

Fig. 6 is a perspective view of the control lever spring for the modified arrangement.

The drawings are to be understood as being more or less of a schematic character for the purposes of disclosing typical or preferred forms of the improvements contemplated herein, and in these drawings like reference characters identify the same parts in the different views.

The particularly clutch disclosed in Figs. 1 and 2 comprises a clutch plate assembly 9 including a disc Ill having thereon the flat friction ring members H, the disc Ill being carried on a rotatable hub l2 splined to driven shaft 8. The clutch plate assembly 9 is disposed between the adjacent face of flywheel l3 and the axially movable pressure member 14 of annular shape. A suitable cover plate I5 of dished cross-section has its rim anchored to the flywheel i3 on the drive shaft 1 and encloses the clutch and its actuating elements. A spring mounting member iii of ringlike shape is arranged back of pressure member l4 and has a relatively wide peripheral flange I i projecting toward the cover plate l5. Compressed thrust springs ID are interposed between the mounting ring l6 and cover plate I5 tending to urge said ring in a direction away from the cover plate and toward the pressure member i4. Retraetor bolts l9 pass through the cover plate i5 and spring mounting ring IS with their headed inner ends 20 engaged in lugs 2| on the pressure plate M and having their threaded outer ends engaged by sleeve nuts 22 that are rotatably mounted in aligned apertures in cover plate I5. Compressed coiled springs 23 surround retractor bolts i9 between spring mounting ring I6 and suitable follower cups 24 that abut the inner ends of the nuts for retracting the pressure member II from the clutch plate.

The spring mounting ring I6 is movably connected to or carried by the cover plate I 5 by means that permit axial movement of the mounting ring toward and from said cover plate. Said means comprise supports, preferably embodying eye-bolts 25 having their heads 28 anchored to the cover plate with their opposite ends slidably engaged in guide bushings 21 in the mounting ring I. The eyes 2! of these bolts 25 have irregularly shaped internal walls of somewhat pearshape, the apical recesses 2!! of which are toward the mounting member l6 and the wider basal portions 30 are toward the bolt heads 28. This arrangement is adapted to accommodate the tilting movements or struts ii that comprise flat compression links disposed with one of their longitudinal edges rockably seated in the apices 2a of the eyes 28 to effect swinging movement of their opposite edges.

Radially positioned release levers 32, which are fulcrumed for swinging or pivotal movement on struts 3i, preferably comprise metal stampings having dished cross-sections for rigidity. These levers have transverse embossments near their outer ends that provide seats 33 on their inside suriaces in which adjacent edges of the struts 3! are engaged to fulcrum said levers for the desired rocking or swinging movement when the inner ends of the levers are moved by a shift collar 3 movable longitudinally of the driven shaft axis. Transverse channels 35 having crowns 36 extend across the outer regions or the levers beyond the struts 3| and these outer regions of the levers terminate in lateral lips 31 thus providing the levers with hook-shaped outer ends for engagement with the walls of apertures 38 in flatted regions lid of the lateral rim ll of spring mounting ring through which these lever ends project. The crowns 38 engaged with the adjacent walls or the apertures 3!) effect a rolling line contact between the levers and the rims of the spring mounting ring. Suitable openings 39 are made in the levers to straddle the eye-bolts 25 that pass therethrough. It will be understood that the struts 3i are long enough to project out or the eyes 28 of the supporting bolts 25 so that the end regions of the struts will engage the seats 33 in the levers 32 on both sides or the openings 39 in said levers.

By reason of the arrangement just described the relatively deep channels 35 and lips 31 at the outer regions or the levers 32 constitute hookshaped elements that function to restrict, to a closely limited degree, any radial movement of the levers toward or away from the axis of the clutch. Also a plurality of fulcrums are provided for each lever that are eflective to accommodate pivotal or swinging movements of the lever. Each lever has a rolling iulcrum at its radially outer end on the rim of spring mounting ring l8. and intermediate its ends said lever has a movable fulcrum on the strut II The mid-region oi the strut edge. which lies closest to the flywheel, fulcrums on the wall of the apical seat 29 in the eye-bolt. when a clutch lever 32 is moved toward the flywheel II to eflect release of the clutch, a rolling action takes place between the outer or crowned fulcrum 3| and the wall of the-hole 38. During this action the intermediate bearing 38 of the lever iulcrums on the edge of the strut that is farthest from the flywheel, and at the same time the strut itself will rock on its opposite edge in the seat 20 of the eye-bolt. In this arrangement the strut is located in the eve-bolt and there is a true rolling action at the fulcrums or the lever.

Suitable anti-rattler or backlash springs 40 are assembled with the levers 32 and the spring mounting ring plate. Each spring to is or substantially U-shape to straddle the lever and includes a pair 0! spaced arms ll connected by a cross piece 42 and there are coils ll at the outer portions of the arms terminating with reversely bent hooks at their extremities. The hooks ll oi said springs are engaged in notches I! at the edge or the spring ring rim II, and the cross pieces 42 at the inner ends oi said springs extend across inner portions of the levers 32. while the intermediate portions or coils I! are engaged with inwardly pressed bosses 46 in adjacent regions of the cover II. It will thus be seen that the two outer contact points A and B oi the springs Ill are substantially in line with the corresponding fulcrum points C and D oi the levers 32. This is quite eflectlve since the springs may be compressed any amount ior suitable tension while assembling the structure, and thereafter the tension which keeps the slack out of the parts will not vary appreciably regardless of the relative positions or the levers. Furthermore, there is no possibility for iatigue oi the springs because there is no material compression of them during operation oi the clutch. The springs rock with the levers and there is very little change in the amount of stress in the coils. This is due to the fact that the intermediate iulcrums oi the springs where they rest against bosses 48 on the cover are so located with relation to the inner and outer ends of the levers that the rocking oi the levers also rocks the springs without changing to any considerable extent the amount of wind or tension or the coils. By reason of the arrangement the backlash spring does not in any way aiiect the thrust spring load of the clutch.

The engagement of the clutch may be accomplished centrifugally through the outward swing of weights 41 having L-shaped legs 48 extending through slots 48 in the spring mounting ring II. The lateral members ill of legs ll provide foot elements interposed between the spring mounting ring l8 and pressure plate ll so that the toe and heel portions 50a and 50b engage in recesses 51 in the adjacent face of said pressure plate that are arranged inwardly from lugs 52 on said pressure plate. The lugs 52 project into the slots is to operatively connect the spring mounting ring l8 and the pressure plate for simultaneous rotative movement but will permit relative axial movement between these elements toward or away from each other. Radially inward oi the slots 49 there are laterally embossed portions in the spring mounting ring it to provide seats 53 for adjacent edges of struts 54. The opposite edges of these struts 54 are engaged in seats II on the feet ill. The heels illb constitute fulcrums for the weights I1 and when these weights swing outward in response to centrifugal force the toes 50a will act on the struts 54 to move the spring mounting ring and pressure plate apart. Thus, the pressure plate will move to the left (Fig. 1) until it engages the clutch plate assembly 9 which will move into engagement with the rotating flywheel, and after a firm contact has been made between these elements the weights will continue to move the spring mounting ring it a desirable distance to th right compressing the thrust springs I! so that the weights may move to the full outermost positions against the spring mounting ring it. This arrangement prevents overloading of the parts because the extreme pressures developed at high rotational speeds are restrained by the spring mounting ring and are not carried through the legs ll 0! the weights to pressure plate it and struts 54. It is desirable to provide some over-travel of the weights to compensate for wear on the facings or friction ring members ll of the clutch plate so that adequate pressure will continue to be developed on said friction members as wear progresses. This .is effectively taken care of by the present struc- -ture.

The central or full-line position of control lever 32 is the position to which this lever is pushed from its right-hand dotted position to prepare the clutch for automatic centrifugal engagement. Lever 32 is restrained in this central position by the usual clutch control linkage (not shown) which holds the release collar 34 against the levers 32 so that they cannot move far to the right. In this position, with the engine idling, pressure plate I4 is clear of the clutch plate 9 so that the clutch is released. When the control lever 32 is moved to the left toward the flywheel l3, by operating the clutch foot pedal, the clutch is manually released sufliciently to entirely overcome the action of centrifugal force on the pressure plate M. This permits the clutch to be manually released at any time regardless of the engine speed. The movement of control lever 32 to its left-hand position (Fig. 1) will move the spring mounting ring iii to the right thus compressing springs I 8 and moving the spring ring and pressure plate assembly away from the fly-wheel and clutch driven plate. The release levers 32 act directly on the spring ring and move the entire assembly, including said ring, the weights 4'! and the pressure plate I as a unit away from or toward the clutch driven member.

In the modified structure shown in Fig. 5, the pressure plate Ha has lateral ears Gil carrying pivot pins 6! that provide fulcrums for the outer regions of the central levers 32a. The cover 62 has a hub portion 63 on which the shift sleeve or collar assembly 64 slides in an axial direction, and the marginal portion of the cover has re cessed brackets 55 that are radially outward from the lever fulcrums 6|. Notches 56 are made in the walls of the bracket recesses to receive adjacent edges of compression links or struts 61 and the opposite edges of these struts are engaged by hook-shaped outer end regions 68 of the levers 32a. The hooked inner ends 69 of the control levers enter radial U-shaped bosses or circumferential flanges ill on shift sleeve 64 where they fulcrum on adjacent edges of struts II, the opposite edges of said struts being engaged in grooves 12 in the opposite walls of recessed bosses i0. Anti-rattler or backlash springs 40a ride at their hooked inner ends 45a on the shift collar or sleeve 64 and have their outer ends that comprise arched cross members 42a seated in slots 13 in the cover brackets 65 in line with the struts iii. The intermediate regions of the spring arms are formed with coils 43a which bear against the pivotal bosses of the levers in line with the fulcrum pins Bi as shown in Fig. 5. In-this modified arrangement, the two outer contact points A and B of the springs 40a are substantially in line with the corresponding fulcrum points C and D of the control levers 32a, and the tension of these springs after assembly will not vary appreciably during operation of the control levers 32a.

While we have described our invention in connection with one specific embodiment thereof, it is to be understood that this is by way of illustration and not by way of limitation and the scope of our invention is defined solely by the appended claims which should be construed as broadly as the prior art will permit.

We claim:

1. In a friction clutch a spring supporting ring; a cover; a supporting member on said cover; a clutch operating lever fulcrumed on said member; and a spring hearing at its inner end on said lever and at its outer end on said ring, an intermediate portion of said spring being fulcrumed on said cover.

2. In a friction clutch a pressure plate; a radially positioned lever for operating said plate, said lever having spaced fulcrums at its outer portion; and yieldable anti-rattler means for said lever, said means having spaced fulcrums arranged substantially inllne with the respective fulcrums of said lever.

3. In a friction clutch a pressure plate; a radially positioned lever for operating said plate, said means providing radially spaced fulcrums for the outer portion of said lever; and an anti-rattler spring for said lever, said spring having radially spaced fulcrums arranged substantially in line with the respective fulcrums of said lever.

4. In a friction clutch a pressure plate; a cover member; a radial lever for operating said plate; radially spaced fulcrums for said lever, at least one of said fulcrums supported by said cover member; and an anti-rattler spring for said lever. said spring having radially spaced fulcrums at least one of which is on said cover member in line with a fulcrum of said lever.

5. In a friction clutch a pressure plate; a member alongside said plate; a radial lever for operating said plate; a strut operatively supported by said member providing a fulcrum for the outer portion of said lever; means providing a second fulcrum for said lever spaced in a radial direction from said strut; and anti-rattler means for said lever comprising a spring having radially spaced fulcrums, one of said fulcrums being in line with said strut and another of which is in line with another fulcrum of said lever.

6. In a friction clutch a pressure plate; a cover; a clutch release lever; a supporting member on said cover having an eye; a strut operating in said eye providing a fulcrum for said lever; means spaced from said strut providing a second fulcrum for said lever; and anti-rattler means for said lever comprising a spring having a fulcrum on said cover in line with said strut, said spring having a second fulcrum in line with the second fulcrum of said lever.

7. In a friction clutch a pressure plate; a cover; a clutch spring supporting ring; a member on said cover for supporting said ring; a lever for operating said pressure plate having a fulcrum on said member: a crowned recess at the outer re ion of said lever engaged with the rim of said ring for providing a second fulcrum for said lever; and anti-rattler means for said lever comprising a spring having a fulcrum on said cover in line with the first named fulcrum of said lever, the outer portion of said spring being engaged with the ring rim in line with the crowned recess of said lever.

8. In a friction clutch, a pressure plate; a cover; a supporting bolt on said cover having an eye; a lever for operating said pressure plate; and a flat member of less width than and extending diametrically across said eye, one edge of said member having rolling engagement with a wall of said eye and the opposite edge of said member having rolling engagement with said lever, said member thereby providing two spaced axes of rotational movement for said lever.

aeeaeae 9. In a friction clutch a preaeure plate: a radially arrana'ed. lever for operating said plate having radially spaced fulcrum: at its outer region: and radially arranged anti-rattler means tor said lever. said means having radially spaced Iulcrums each of which is approximately in axial alignment with a fulcrum of said lever.

HAROLD NUTT.

LEO W. COOK.

REFERENCES CITED Number Name Date 594,499 Dodge Feb. 19, 1995 Number Number 8 Name Date Soofleld May 6, 1924 Rockwell May 2, 1933 Nutt May 15, 1934 Wemp Am. 21, 1986 Nutt et al. Nov. 24, 1936 Nutt et al. Apr. 26, 1938 Reed July 22, 1941 Anderson Aug. 6, 1941 Nutt Jan. 2, 1945 FOREIGN PATENTS Country Date Great Britain July 1, 1933 

